Supplemental animal feedstuffs fortified with nutritive supplements have been developed in block form to permit free choice feeding and reduce the labor required for mixing the nutritive supplement with the animals' feed ration. Such nutritive supplement blocks include, for example, salt blocks, mineral blocks, protein blocks and molasses blocks.
Compressed blocks or blocks formed by evaporating substantial amounts of water from a feedstuff mixture are known in the art. For example, Bartle et. al., U.S. 2003/0118690 describe a block having high fat content, wherein the block is pressed into tubs.
Skoch et. al., U.S. Pat. No. 4,171,385 describe molasses-based feed blocks wherein magnesium oxide is employed as an ingredient to form a pourable heated composition that self-hardens after cooling into a solid, weather resistant feed block suitable for ruminant consumption. Such feed blocks have the advantage of ease of manufacture, since pourability is provided and hardening of the block occurs without the need to evaporate water, leading to lower manufacturing costs and lower energy consumption in the finished product compared to blocks where water evaporation is necessary.
High fat content in a pourable self-hardening feed block, including fat content of 7 wt % or more, is desirable for current farm productivity practices and provides higher energy content per weight unit of the feed block. While a pourable feed block having fat content of 7 wt % or more can be formed, several problems arise during both manufacturing and use of such feed blocks. Higher fat content increases the viscosity of the liquid mixture, making the mixture difficult to pour. Further, the high fat content noticeably softens the solidified blocks. Softer blocks allow overconsumption by animals when provided as a free choice feed supplement. Still further, pourable molasses based high fat content blends tend to partially separate during solidification, leading to a surface layer of solidified fat or oily residue on the solidified block.